General Biology 2nd Quarter Reviewer PDF

GENERAL BIOLOGY FIRST SEMESTER: Second Quarter Notes/Reviewer - Soyon Cinco ○ The cell grows and the nuclear THE CELL CYCLE AND INTERPHASE DNA is duplicated...

GENERAL BIOLOGY FIRST SEMESTER: Second Quarter Notes/Reviewer - Soyon Cinco ○ The cell grows and the nuclear THE CELL CYCLE AND INTERPHASE DNA is duplicated ○ The three stages are Gap 1, Synthesis, and Gap 2 ★ Cell Division ○ In order for a cell to move from ○ The process by which a parent cell interphase in to the mitotic phase, divides into two daughter cells many internal and external ○ All cells reproduce by splitting into conditions must be met two, where each parental cell gives ○ Interphase is longer because if the rise to daughter cell cells are not fully prepared it may ★ Why do we need cell division? cause mutations ○ All multicellular organisms use cell division for growth and the maintenance and repair of cells and tissues ○ Single-celled organisms use cell division as their method of reproduction ○ All humans have different amount of cells ★ Gap 1/Growth 1 ○ Damaged cells get replaced ○ Cell grows and more organelles through cell division are produced increasing the ★ Cell Cycle volume of the cytoplasm ○ Ordered series of events involving ○ Cell is active at the biochemical cell growth and cell division that level (ATP, Lipid, Carbs, Glucose) – produces two new daughter cell this is the event that causes ○ Cells on the path to two identical organelle biogenesis (clone) cells ○ Accumulates building blocks of ○ Has two major phases chromosomal DNA and associated Interphase proteins Mitotic Phase ○ Accumulates sufficient energy reserves to complete the task of INTERPHASE replicating chromosomes in the nucleus ★ Interphase ○ Histone protein is packed ○ The cell undergoes normal growth ○ A large amount of ATP processes while also preparing for accumulates energy cell division ★ Mitochondria ○ Preparation for cell division ○ Generator for energy PAGE 1 ★ Organelle Biogenesis cell it will equal to 23 pairs to each ○ The process by which new daughter cells organelles are made ★ Pituitary Gland ○ Duplication of the cell organelle ○ Control of cell cycle ★ Gap 1 Checkpoint ○ Master gland ○ External influences such as growth ○ Responsible for correction of cell factors, play a large role in sperm checkpoint carrying the cell to pass the G1 ★ Centrosomes Checkpoint ○ Organize the microtubules ○ Check for genomic DNA damage ○ Maintain equal distribution of ○ Cell size and protein reserves are chromosomes in daughter cells assessed ○ 1 centrosome = 2 centrioles ○ Cell can halt the cycle and attempt ○ 1 centriole = 27 microtubules to remedy the problematic ○ Dimer (alpha & beta) tubulin = 54 condition, or the cell can advance (27 each) in to G0 and await further signals ○ 2 centrioles = 108 tubulin when conditions improve ○ There are 108 tubulin because in 1 centrosome there are 2 centrioles ○ G0 - setting if the cell is damaged and each centriole consist of 54 ★ Synthesis microtubules from the alpha and ○ Chromatin begins to condense beta tubulin ○ DNA replication results in the ★ Centrioles formation of identical DNA-sister ○ Help organize cell division chromatids ○Not present in the centrosomes of ○ Centrosome is duplicated other eukaryotic species Centrosome separates ★ Chromosomes during anaphase to form ○Made up of two chromatids spindle fibers attached to the centromere Microtubules from the ★ Chromatids centrosome that form ○ Made up of condensed chromatin spindle fibers pull the sister ★ Chromatin chromatids towards ○ Untangled DNA and protein opposite poles of the cell ★ Gap 2/Growth 2 during anaphase ○ The cell replenishes its energy ○ The two centrosomes will give rise stores and synthesize proteins to the mitotic spindle, the necessary for chromosome apparatus that orchestrates the manipulation movement of chromosomes during ○ Some cell organelle are duplicated mitosis ○ Synthesize protein for ○ We have 46 pairs of chromosomes, chromosomal manipulation we have 46 because if we half the ○ The cytoskeleton dismantles the chromosomes of the parent ○ There may be additional cell growth during G2 PAGE 2  ○ The final preparations for the ○ G0 specialized cell mitotic phase must be completed before the cell is able to enter the MITOTIC PHASE first stage of mitosis ○ When organelles duplicate, cell will ★ Mitotic Phase grow ○ A multistep process during which ○ Small and large subunit of the the duplicated chromosomes are ribosome for protein synthesis and condensed, aligned, separated, chromosomal manipulation and moved to opposite poles of ★ Gap 2 Checkpoint the cell, and then are divided into ○ Bars entry to mitotic phase if two new identical daughter cells certain conditions are not met ○ The actual cell division process ○ Ensures that all chromosomes ○ Formation of two daughter cells have been replicated ○ Types ○ Replicated DNA is not damaged Mitosis - somatic cells ○ If a problem is detected: cell cycle Meiosis - sex cells (gamete) is halted to complete replication or ○ Parts repair the damaged DNA Karyokinesis ★ Mitotic spindle/spindle fiber ○ Formed during cell division after Cytokinesis the cytoskeleton is dismantled ★ Mitosis ★ G0 Phase ○ For body cells ○ Cells are not actively preparing to ○ Includes the: prophase, metaphase, anaphase, telophase, divide and cytokinesis ○ Cells exit the cell cycle ○ Result in formation of the daughter ○ Some cells enter G0 temporarily cells with same amount and kind until an external signal triggers the of chromosomes as the parent cell onset of G0 ★ Meiosis ○ Other cells that never or rarely ○ For reproductive cells/gametes divide such as mature cardiac ○Cell division that result in the muscle and nerve cells, formation of four daughter cell permanently remain in G0 each with half the number of ★ Rates chromosomes of the parent cell ○ Cultured mammalian cells: 24 ★ Karyokinesis hours ○ Movement of nucleus ○ G1: 9 hours ○Only in eukaryotic cells because ○ S: 10 hours prokaryotes have no nucleus ○ G2: 4 ½ hours ★ Cytokinesis ○ M: ½ hour ○ Movement of cell separation ○ Few hours in Early embryonic ★ M Checkpoint development ○ Spindle Checkpoint ○ 5 days for epithelial cells PAGE 3  ○ Occurs near the end of the oncogene when they become metaphase stage of karyokinesis mutated ○ Determines whether all the sister ★ Positive Regulator chromatids are correctly attached ○ Molecules that promote progress to the spindle fiber of the cell cycle to the next phase ○ This is important because if it is ○ Human Epidermal Growth not attached it may caused Receptor 2 (HER 2) disorders such as Down Syndrome Positive regulator in the (Trisomy 21) breast which can cause breast cancer CELL CYCLE REGULATION ★ Negative Regulator ○ Molecules that halt the cell cycle ○ May act independently or ★ Cell Cycle influence independently the ○ Controlled by the regulatory cells activity or production of regulatory and it regulates the cell cycle proteins ★ Cancer ○ Result of unregulated process of the cell cycle due to the POSITIVE REGULATION breakdown of the mechanism that controls the entire process ★ Cyclin ★ Proto-oncogenes ○ Proteins associated with the cell ○ Genes that code for positive cycle of cell division which are regulators during cell cycle thought to initiate certain ○ Normal genes that, when mutated processes of mitosis in certain ways, become ○ Act in conjunction with Cdk to oncogenes, genes that cause a cell regulate cell cycle by to become cancerous phosphorylating key proteins ★ Tumor-suppressor genes ○ Fluctuate through the cell cycle ○ Healthy normal genes that slow ★ Mitotic Cyclin down cell division ○ Synthesized during S & G2 phases ○ Helps to repair DNA mistakes and ★ Kinase also cell apoptosis or cell death ○ Enzyme that catalyzes the transfer ○ Segments of DNA that codes for of phosphatase groups from regulator proteins that prevent the high-energy phosphate-donating cell from undergoing uncontrolled molecules to specific substrate division ★ Cyclin-dependent Kinase (CDK) ★ Oncogenes ○ Functions in phosphorylating other ○ Genes that cause the cell to protein become cancerous ○ Regulates the cell cycle when ○ Both proto-oncogene and tumor bound to cyclin suppressor gene can be an PAGE 4  ★ Oxygen ○ Allows us to produce ATP phosphate needed for the structure of DNA ★ G2 ○ Histones for condensation ○ Microtubules associated protein PHASE CYCLIN CDK PROTEIN for the depolymerization and separation of G1 D 4 and 6 Histones and Rb centrosome and formation Protein of spindle fiber S E 2 Histone and Rb ○ Nuclear lamins protein Cardiogenesis G2 A 1 or 2 Histones, Maintains the structure of microtubules nuclear lamina associated ★ M protein, and ○ Cytokinesis nuclear lamins ○ The enzymes in the cytokinesis M B 1 Enzymes in present in the golgi apparatus are cytokinesis the protein present in the Golgi apparatus ★ G1 ○ Histones for DNA replication ○ Has Retinoblastoma protein which release E2F ★ E2F ○ Transcription factor for DNA ★ Nucleosome replication ○ Subunit of chromatin composed of ○ G1 to S transition a short length of DNA wrapped ★ S around a core of histone proteins ○ Through hydrolysis ATP -> ADP ★ Histones ○ PO4 or Phosphate Molecule comes ○ Associates with DNA to form from ATP nucleosomes PAGE 5  ○ First level of DNA organization in a ★ Apoptosis eukaryotic cell is maintained by ○ Cell death this molecule ○ The leftover organelles are eaten ★ Protein by the phagocytes, white blood ○ Functions of this is for DNA cells, and etc. replication ★ Hypoxia ○ Low oxygen ○ Causes damage to cell because NEGATIVE REGULATION cells need cellular respiration meaning it needs oxygen ★ Retinoblastoma Protein ○ DNA is composed primarily with ○ Group of tumor suppressor oxygen proteins common in many cells ○ Negative if it is not phosphorylated ○ Positive if it is phosphorylated ★ P53 and P21 ○ P53 and P21 are protein in kilodaltons ○ These proteins were damaged or nonfunctional cells that replicate uncontrollably ○ Act primarily in G1 checkpoint when damaged DNAs were detected ★ P53 ○ Recruits enzymes to repair DNA and trigger the production of p21, cell cycle halt, inhibitor of cyclin-dependent kinase by preventing Rb phosphorylation ○ Regulates cell growth and monitors DNA damage ○ Halts progression of cell cycle ★ P21 ○ Binds with CDK and prevent rb phosphorylation ○ Inhibits cell cycle ○ Levels are controlled by p53 ★ Nitrogen Bases ○ Composition of amino acids that can manipulate DNA PAGE 6